Claire Dearden, MBBS, MD, FRCP, FRCPath from the Royal Marsden Hospital, London, UK discusses the latest drug in CLL treatment, venetoclax at the 2017 British Society for Hematology (BSH) Annual Scientific Meeting in Brighton, UK. There are various regulations in place for venetoclax before it can be administered to a patient such as, the patient must have failed or is intolerant to alternative therapy involving B-cell receptor inhibitors. Response rates for venetoclax are very high and can even result in MRD negative responses. The administration of venetoclax results in the unblocking of BCL-2, causing rapid cell apoptosis. This in turn releases a high volume of chemicals into the body, left untreated this can result in tumor lysis syndrome (TLS). Therefore, it is crucial that administration of treatment is gradual as to mitigate the TLS risk. This video has been supported by Napp Pharmaceuticals Ltd through an unrestricted educational grant to Magdalen Medical Publishing.